Get operator overloads
via Digitalmars-d-learn
digitalmars-d-learn at puremagic.com
Tue Sep 2 12:21:01 PDT 2014
On Tuesday, 2 September 2014 at 18:55:50 UTC, Ivan Timokhin wrote:
> Is it possible to get all overloads of an operator for a
> particular type?
>
> I.e., having this struct definition, is it possible to tell at
> compile time that it can be added with double and int[]?
>
> struct S
> {
> void opBinary(string op : "+")(double);
> void opBinary(string op : "+")(int[]);
> }
>
> To clarify, I am well aware that it can also be overloaded
> through the second argument via opBinaryRight, but for now I'm
> only interested in overloads provided by S itself.
>
> I've tried __traits(getOverloads), but with no success:
> __traits(getOverloads, S, "opBinary") returns empty tuple,
> and __traits(getOverloads, S, `opBinary!"+"`) results in a
> compilation
> error (dmd 2.065):
>
> Error: no property 'opBinary!"+"' for type 'S'
> Error: (S).opBinary!"+" cannot be resolved
I can't answer the question about inspecting the overloads, but
if you just want to know whether it supports addition, the
idiomatic way is to test whether it compiles:
enum supportsAddition(S) = is(typeof(S.init + 0.0));
static if(supportsAddition!MyType) { ... }
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